Vacuum chuck apparatuses and electrostatic chuck apparatuses are among this kind of substrate suction apparatuses.
A vacuum chuck apparatus embodies a vacuum suction technology of sucking up a substrate by sucking away the air between the substrate and the chuck apparatus so as to create a negative pressure therebetween. Since the apparatus sucks up the whole surface of a substrate with a strong negative pressure, it is possible to suck up even a substrate easy to warp while restraining it from warping. However, vacuum chuck apparatuses cannot be utilized under a vacuum atmosphere without gas. Therefore, they are not applicable to apparatuses utilizing vacuum such as plasma processing apparatuses, ion implantation apparatuses, ion doping apparatuses, liquid crystal substrate compositing apparatuses, exposure apparatuses of electron beam, EUV and the like, wafer inspection apparatuses, etc.
On the other hand, an electrostatic chuck apparatus can be utilized either under a vacuum atmosphere or under an air atmosphere because it electrostatically attracts up a substrate by virtue of electrostatic force acting between the substrate and the apparatus. Therefore, electrostatic chuck apparatuses are positioned as indispensable in the recent semiconductor manufacturing technologies which employ a great number of apparatuses utilizing vacuum. However, since the electrostatic chuck apparatuses are not provided with a strong suction power, it is more difficult for them than the vacuum chuck apparatuses to deal with warping of the substrates.
In view of the above problems, as disclosed in the following Patent Documents 1 to 4, there are proposed substrate suction apparatuses which include a vacuum suction mechanism and an electrostatic attraction mechanism.
By employing these apparatuses, inside an exposure apparatus and the like, for example, an exposure process and the like can be carried out under a vacuum atmosphere by first flattening a warped substrate through vacuum suction and then switching it to electrostatic attraction.
Patent Document 1: Japanese Patent Application Publication No. 2003-318160;
Patent Document 2: Japanese Patent Application Publication No. 2003-107487;
Patent Document 3: Japanese Patent Application Publication No. 2007-053405;
Patent Document 4: Japanese Patent Application Publication No. 2005-109358; and
Patent Document 5: Japanese Patent Application Publication No. 2004-298970.